Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
SYS.OK|MANUAL.DB● LIVE
HOMESERVICE MANUALSJAGUAR1991XJ-6 L6-4.0LREPAIR AND DIAGNOSISPOWERTRAIN MANAGEMENTEMISSION CONTROL SYSTEMSTESTING AND INSPECTIONLACK OF POWER
1991 Jaguar XJ-6 L6-4.0L
Lack of Power
1991 Jaguar XJ-6 L6-4.0LSECTION Lack of Power
Engine delivers less than expected power. Little or no increase in speed on slight acceleration.
POSSIBLE CAUSE ACTION
Spark timing - excessive retard Refer to COMPUTERS AND CONTROL SYSTEMS.
Initial timing incorrect Refer to COMPUTERS AND CONTROL SYSTEMS.
Restricted exhaust Check Catalytic Converter. Catalytic Converter
Poor or contaminated fuel Recommend higher grade fuel
EVAP system malfunction Check EVAP system. Evaporative Emissions System
POSSIBLE CAUSE ACTION
Spark timing - excessive retard Refer to COMPUTERS AND CONTROL SYSTEMS.
Initial timing incorrect Refer to COMPUTERS AND CONTROL SYSTEMS.
Restricted exhaust Check Catalytic Converter. Catalytic Converter
Poor or contaminated fuel Recommend higher grade fuel
EVAP system malfunction Check EVAP system. Evaporative Emissions System
RENDER: 1.0x
NO RELATED
Recommended Tools & Savings
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
Affiliate disclosure: We may earn a commission at no extra cost to you.
When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.